We have completed maintenance on DiscoverMagazine.com and action may be required on your account. Learn More

#43: Next-Level Quantum Spookiness

Photons instantaneously send signals over 11 miles. Einstein remains perplexed.

By Stephen Ornes
Dec 14, 2008 6:00 AMNov 12, 2019 5:48 AM


Sign up for our email newsletter for the latest science news

Using two villages on opposite sides of Gen­eva as their lab, Swiss physicists have taken one of the strangest phenomena of quantum mechanics to a new level. From Geneva they sent a pair of photons along fiber-optic cables [pdf], one to each village. When they measured one photon upon its arrival, the other changed instantaneously —though it was 11 miles away. This weird linkage, called quantum entanglement, raises exotic possibilities like teleportation. When two particles are entangled, the measurement of one immediately affects the other, no matter how distant. It’s so counter­intuitive that Albert Einstein dismissed it as “spooky action at a distance.” Such entanglement had been observed before, but never over such a great distance.

One might assume that one particle sent an ultrafast signal to its partner, says physicist Nicolas Gisin, a member of the University of Geneva team. If that were true, the quantum communiqué would have traveled at more than 10,000 times the speed of light, something difficult to reconcile with the known laws of physics. “Nature does not function that way,” Gisin says. In relativity theory, communicating faster than light speed is not possible. But the correlations observed in entangled photons cannot be used to communicate any kind of signal, so they do not violate the theory. Still, Gisin says, “We have to admit this is a really big conceptual change.”

1 free article left
Want More? Get unlimited access for as low as $1.99/month

Already a subscriber?

Register or Log In

1 free articleSubscribe
Discover Magazine Logo
Want more?

Keep reading for as low as $1.99!


Already a subscriber?

Register or Log In

More From Discover
Recommendations From Our Store
Shop Now
Stay Curious
Our List

Sign up for our weekly science updates.

To The Magazine

Save up to 40% off the cover price when you subscribe to Discover magazine.

Copyright © 2024 Kalmbach Media Co.